1. The Field of the Invention
The present invention relates generally to pressurized gas springs and, in particular, to the provision in such gas springs of means for controlling the extension force, i.e. push-out force, exerted on the piston rod of the spring by the internal gas pressure as a function of temperature.
2. The Prior Art
DE-OS No. 2,526,437 discloses a door closer having a gas spring provided with a throttling valve that is variable as a function of temperature. While this results in a uniform speed of travel of the piston rod over a temperature interval, the extension force of the piston rod is not controlled as a function of temperature. A temperature increase results in a pressure rise in the working chamber of the gas spring, and hence an extension force that increases proportionally to the temperature rise.